Biogenic amines content in different wine samples

Twenty-five samples of different Slovak wines before and after filtration were analysed in order to determine the content of eight biogenic amines (tryptamine, phenylalanine, putrescine, cadaverine, histamine, tyramine, spermidine and spermine). The method involves extraction of biogenic amines from wine samples with used dansyl chloride. Ultra-high performance liquid chromatography (UHPLC) was used for determination of biogenic amines equipped with a Rapid Resolution High Definition (RRHD), DAD detectors and Extend-C18 LC column (50 mm x 3.0 mm ID, 1.8 mu m particle size). In this study the highest level of biogenic amine in all wine samples represent tryptamine (TRM) with the highest content 170.9 +/- 5.3 mg/L in Pinot Blanc wine. Phenylalanine (PHE) cadaverine (CAD), histamine (HIS) and spermidine (SPD) were not detected in all wines; mainly SPD was not detected in 16 wines, HIS not detected in 14 wines, PHE and CAD not detected in 2 wines. Tyramine (TYR), spermine (SPN) and putrescine (PUT) were detected in all wines, but PUT and SPN in very low concentration. The worst wine samples with high biogenic amine content were Saint Laurent (BF), Pinot Blanc (S) and Pinot Noir (AF).European Community [26220220180]; VEGA [1/0611/14

Fungal diversity in the grapes-to-wines chain with emphasis on Penicillium species

The aim of this work was the description of surface and endogenous mycobiota colonisation of grapes, fresh grape juice, grape must, and wine primarily focused to the current spectrum of the penicillium species. One sample of white grape variety Palava and one sample of blue grape variety Dornfelder were collected in Small Carpathian wine growing region of Slovakia in the year 2017. Direct plating of grapes on agar plates was used for analysis of surface mycobiota of grapes while surface sterilsed grapes were used for endogenous mycobiota analysis. Mycobiota of juice, must, and wine was analysed by plate dilution method. Overall, we isolated 148 strains belonging to 13 genera of filamentous microscopic fungi and Mycelia sterilia from grape variety Palava, while the most frequent was Alternaria. Alternaria was the most common genus in the surface and endogenous colonisation with an average relative density 50% and 73.6%, respectively. A total of 2 species of Penicillium were detected from the grapes to wine, potentially toxigenic Penicillium expansum and P. chrysogenum. A total of 39 strains belonging to 6 genera and Mycelia sterilia were identified from grape variety Dornfelder. The most abundant genus was also Alternaria (51.3%), followed by Penicillium (12.8%). Alternaria was the most common genus in the surface and endogenous colonisation  and fresh grape juice with an average relative density from 20% (grape juice) to 71% (endogenous colonisation of grapes). A total of 3 species of Penicillium were detected from the grapes to wine, where Penicillium expansum were detected most commonly. In the second part of our work some selected isolates were tested to the ability to produce mycotoxins such as patulin, citrinin, and roquefortin C in in vitro condition by thin layer chromatography method. All tested  strains of Penicillium species were able to produce at least one mycotoxin.&nbsp

Mycotoxin-producing Penicillium spp. and other fungi isolated from grapes for wine production in Small Carpathians wine region

The diversity of mycobiota associated with grapevine in Vrbove, Slovakia at the harvest time in 2018 was evaluated. Fourteen samples of grapes were analyzed by plating methods and by plating methods with surface disinfection. The identification of fungi was performed using the morphological and microscopical characteristics. From the 1001 strains detected and identified from exogenous mycobiota, the most frequent genera were Alternaria, Rhizopus and Sordaria. Their relative density was low, except Alternaria. The most frequently encountered moulds and with the highest relative density from endogenous mycobiota were Alternaria, Cladosporium and Penicillium. Most of all genera had relative density less than 1%. Penicillium contributed small proportion in both sources. Penicillium citrinum was the most dominant species in exogenous and endogenous mycobiota. Penicillium expansum and P. glabrum were recorded in exogenous source and P. hordei, P. chrysogenum and P. griseofulvum in endogenous. Potentially toxigenic Penicillium species were tested for their toxigenic ability by thin layer chromatography method. Out of 15 tested isolates representing five potentially toxigenic species 11 produced at least one mycotoxin. Positive toxinogenity was detected in all tested strains of Penicillim citrinum (9/9)

Microbiological evaluation of poultry sausages stored at different temperatures

The aim of our study was to evaluate the microbiological quality of poultry sausages, which were stored at different temperatures (4 °C, 15 °C). Total count of bacteria, coliform bacteria, yeasts and filamentous microscopic fungi were detected in poultry sausages. Microbiological quality was evaluated using the horizontal method for the determination number of microorganisms. Total count of bacteria in sausages stored at 4 °C ranged from 1 × 101 CFU.g-1 in sample 1 (after opening) to 4.35 × 104 CFU.g-1  in sample 1 (7th day of storage). Total count of bacteria in sausages stored at 15 °C ranged from 3.25 × 103 CFU.g-1 in sample 1 (after opening) to 3.12 × 106 CFU.g-1 in sample 1 to 3.12 × 106  CFU.g-1 in sample 1 (7th day of storage).  Coliform bacteria in sausages stored at 4 °C ranged from 1 × 101 CFU.g-1 to 3.15 × 105 CFU.g-1. Coliform bacteria in sausages stored at 15 °C ranged from 1.54 × 103 CFU.g-1 to 1.40 × 106 CFU.g-1.  Yeasts and microscopic filamentous fungi in sausages stored at 4 °C ranged from 2.75 × 104 CFU.g-1 to 1.40 × 106 CFU.g-1.  Yeasts and microscopic filamentous fungi in sausages stored at 15 °C ranged from 1.30 × 104 CFU.g-1 to 1.44 × 106  CFU.g-1. Total count of bacteria, coliform bacteria, yeast and microscopic fungi were not in accordance with Codex Alimentarius of Slovak Republic on 3rd day in samples stored at 15 °C

Effect of selected feed additives on internal quality parameters of table eggs

The aim of our experiment was to evaluate under experimental conditions the influence of probiotic preparation based on lactobacillus, oregano essential oil, sumac (Rhus coriaria), propolis and pollen on egg quality parameters of laying hens hybrid Lohman Brown. For housing hens (n ​​= 60) three storey enriched battery cage was used in which hens were divided in groups (n = 10). Total floor space given to one animal was 943.2 cm2. In the control group of hens complete feed mixtures without any additions were fed. In the first experimental group complete feed mixture was enriched with probiotic lactobacilli based preparation in a dose of 0.5 g.kg-1. In the second experimental group oregano essential oil was added to the feed mixture at a dose of 0.5 ml.kg-1. The third experimental group was enriched with 1 % concentration of sumac (Rhus coriaria). The fourth experimental group was enriched with 0.2 g of propolis extract per 1 kg of feed mixture and the fifth experimental group was supplemented by pollen extract of the same dose. All groups were fed ad libitum. Eggs quality indicators observed were egg weight (g), yolk percentage (%), yolk index, white percentage (%), whites index and Haugh units of whites (HJ). The results show that addition of probiotics positively, although not significantly, influenced the average egg weight. The addition of oregano oil and sumac insignificantly decreased egg weight (P>0.05), the values ​​of the other eggs quality indicators were comparable with the control group. Supplementation of feed mixture with propolis as well as phytobiotics insignificantly decreased egg weight, but its addition improved the internal quality parameters as the yolks and whites index, whose average values ​​were in this group, although not statistically significantly higher (P>0.05).

Yeast diversity in new, still fermenting wine "federweisser"

The aim of this study was to isolate and identify yeasts in different new wine "federweisser" samples. We collected the samples at the end of the August 2015 and in the middle of the September 2015. Used 15 new wine samples in this study (5 white and 10 red) were from the local Slovak winemakers. Irsai Oliver (3), Moravian Muscat (2), Agria/Turan (1), Dornfelder (3), Blue Frankish (3), Pinot Noir (1) and Saint Laurent (2). Three cultivation media were used for detection of yeasts in "federweisser" samples. Malt extract agar base (MEA), Wort agar (WA) and Wild yeast medium (WYM) were used for the cultivation of yeasts. Cultivation was performed by spread plate method. Ethanol/formic acid extraction procedure was used for preparation of samples. MALDI-TOF Mass Spectrometer (Microflex LT/SH) (Bruker Daltonics, Germany) was used for the identification of yeasts. We identified seven different strains of Saccharomyces cerevisiae (23; 70%), two strains of Kloeckera apiculata [teleomorph Hanseniaspora uvarum] (7; 21%), and one strain of Pichia kluyveri (1; 3%), Pichia occidentalis [anamorph Candida sorbosa] (1; 3%) and Metschnikowia pulcherrima (1; 3%) in 15 new wine "federweisser" samples. Saccharomyces cerevisiae was dominant species in each new wine sample, and formed creamy convex colonies with circular edge. Metschnikowia pulcherrima formed convex to pulvinate, circular white-pink colored colonies, Kloeckera apiculata formed flat, circular smooth colonies with turquoise center with gray edge, Pichia occidentalis formed irregular pulvinate light-cream colored colonies, and Pichia kluyveri formed turquoise, convex, undulate and smooth colonies on Malt extract agar base with bromocresol green

A thaumatin-like genomic sequence identification in Vitis vinifera l., stormy wines and musts based on direct pcr

Direct polymerase chain reaction method was use to amplify a thaumatin-like sequence of Vitis vinifera L. in grapes as well as in stormy wines and musts. Thaumatin-like proteins (TLPs) of Vitis vinifera possess beside its function in abiotic and biotic stress response another one - they are able to cause protein haze in wine unless removed prior to bottling. Direct PCR is an approach where omission of DNA extraction is typical prior the amplification of the target site of plant genome. Crude extract or small pieces of plant tissues are used in the analysis directly without steps of extraction and purification of gDNA. The biological material that was used in analysis was collected during August - October 2017 in local stores and winery Sabo and comprises from cultivars Iršai, Muškát, Savignon Blanc, Svätovavrinecké, Dornfelder and Pálava. Direct PCR was performed by a cutted piece of grape tissue and a dilution buffer was use in 1:2 for stormy wine or must, respectively. Direct amplification of thaumatin-like protein sequence of Vitis vinifera was performed along with the control reactions with the primers for conserved region of plant chloroplast. Possitive amplification of thaumatin-like allergen sequence resulted in 570 bp amplicon. The most abundant amplicons were amplified in stormy wines, followed by musts and the amplicons from grapes were weaker when comparing them to others. The amplicon specificity checking of obtained PCR product of thaumatin-like allergen was performed by restriction cleavage by Psi I and resulted in restriction amplicons of the 80 bp, 81 bp, 94 bp and 315 bp in length. Confirmation of the amplicon specificity by restriction cleavage support the potential of direct PCR to become a reproducible method that will be fully applicable in routine analysis of not only plant genomes in the future, but it was demonstrated, that it works in liquids, too.

Evaluation of microbiological quality of selected cheeses during storage

The aim of this article was to evaluate and compare the microbiological quality of selected types of cheeses immediately after opening and after 5 days storage in the refrigerator. Total viable counts (TVC), coliform bacteria (CB) and microscopic filamentous fungi (MFF) were determined by microbiological analysis. We analyzed 8 samples of cheese of Slovak origin. Plate dilution method was used for microbiological analysis. The Codex Alimentarius of Slovak republic (2006) just indicates number of coliforms bacteria (102) and microscopic fungi (5 × 102). The TVC values after opening of cheeses ranged from 1.68 × 103 CFU.g-1 (3.22 log CFU.g-1) in the sample no. 1 to 1.71 × 105 KTJ.g-1 (5.23 log CFU.g-1) in the sample no. 4 after storage in the refrigerator. All samples were negative for the presence of coliform bacteria after opening. The values of CB were 1.18 × 102 CFU.g-1 (2.07 log CFU.g-1) in sample no. 7 and 1.90 × 102 CFU.g-1 (2.27 log CFU.g-1) in the sample no. 8 after storage in refrigerator. These values are not in accordance with Codex Alimentarius of Slovak Republic (2006). Other samples were negative for presence of CB after storage at 4 °C. The values of MFF in samplesranged from 1.81 × 101 CFU.g-1 (1.25 log CFU.g-1) in the sample no. 1 after opening to 1.68 × 102 CFU.g-1 (2.22 log CFU.g-1) in sample no. 7 after storage of samples. All analysed samples were in accordance with Codex Alimentarius of Slovak republic (2006).

Oxidative stability of chicken’s breast after vacuum packaging, EDTA, sage and rosemary essential oils treatment

In the present work, the effect of the sage and rosemary essential oils on oxidative stability of chicken breast muscles during chilled storage was investigated. In the experiment were chickens of hybrid combination Cobb 500 after 42 days of the fattening period slaughtered.  All the broiler chickens were fed with the same feed mixtures and were kept under the same conditions. The feed mixtures were produced without any antibiotic preparations and coccidiostats. After slaughtering was dissection obtained fresh chicken breast with skin from left half-carcass, which were divided into five groups (n = 5): C - control air-packaged group; A1 - vacuum-packaged experimental group; A2 - vacuum-packaged experimental group with EDTA solution 1.50% w/w; A3 - vacuum-packaged experimental group with Salvia officinalis L. oil 2.0% v/w and A4 - vacuum-packaged experimental group with Rosmarinus officinalis L. essential oil 2.0% v/w. The sage and rosemary essential oils were applicate on surface chicken breasts and immediately after dipping, each sample was packaged using a vacuum packaging machine and storage in refrigerate at 4  ±0.5 °C. The value of thiobarbituric acid (TBA) expressed as amount of malondialdehyde (MDA) in 1 kg sample was measured during storage in 1st, 4th, 8th, 12th and 16th day. The treatments of chicken breasts with sage and rosemary essential oils show statistically significant differences between all testing groups and control group, where higher average value of MDA measured in breast muscle of broiler chickens was in samples of control group (0.396 mg.kg-1) compared to experimental groups A1 (0.060 mg.kg-1), A2 (0.052 mg.kg-1), A3 (0.042 mg.kg-1) and A4 (0.041 mg.kg-1) after 16-day of chilled storage. The results of experiment showed that the treatment of chicken breast with sage and rosemary essential oils had positive effect on the decrease of oxidative processes in breast muscles during chilling storage and use of plant essential oils is one of the possibilities increase shelf life of fresh chicken meat